Sure, Julian, but this is only true in OPS/RAC environment.

I think we are talking about single instance environment here. However it si good you brought this up, because in OPS this definitely is one of the most important factors when deciding the database block size (of course if applications are not/can't be partitioned in a great extent). But for single instance databases I still don't see any realy good reason why OLTP should not have big block size.